[tests] Refactor VLM detection in studio

studio/backend/tests/test_vision_cache.py

@@ -117,6 +117,18 @@ def test_subprocess_called_once_with_cache(self, mock_needs_t5, mock_subprocess)
         mock_subprocess.assert_called_once()
         assert _vision_detection_cache[("unsloth/Qwen3.5-2B", None)] is True
 
+    @patch("utils.models.model_config._raw_config_has_vision_config", return_value = True)
+    @patch("utils.models.model_config._is_vision_model_subprocess", return_value = None)
+    @patch("utils.transformers_version.needs_transformers_5", return_value = True)
+    def test_subprocess_none_falls_back_to_raw_vision_config(
+        self, mock_needs_t5, mock_subprocess, mock_raw_config
+    ):
+        assert is_vision_model("unsloth/gemma-4-E4B-it") is True
+        assert is_vision_model("unsloth/gemma-4-E4B-it") is True
+
+        mock_subprocess.assert_called_once()
+        mock_raw_config.assert_called_once_with("unsloth/gemma-4-E4B-it", hf_token = None)
+
 
 # ---------------------------------------------------------------------------
 # Exception handling — cache the False fallback
@@ -223,6 +235,20 @@ def test_vision_config_attr_detected_and_cached(
         assert is_vision_model("Qwen/Qwen2-VL-7B") is True
         mock_load_config.assert_called_once()
 
+    @patch("utils.transformers_version.needs_transformers_5", return_value = False)
+    @patch("utils.models.model_config.load_model_config")
+    def test_model_type_prefix_detected_and_cached(
+        self, mock_load_config, mock_needs_t5
+    ):
+        cfg = MagicMock(spec = [])
+        cfg.model_type = "gemma4audio"
+        cfg.architectures = ["Gemma4AudioForCausalLM"]
+        mock_load_config.return_value = cfg
+
+        assert is_vision_model("google/gemma-4-audio") is True
+        assert is_vision_model("google/gemma-4-audio") is True
+        mock_load_config.assert_called_once()
+
     @patch("utils.transformers_version.needs_transformers_5", return_value = False)
     @patch("utils.models.model_config.load_model_config")
     def test_audio_model_excluded_and_cached(self, mock_load_config, mock_needs_t5):

studio/backend/utils/models/model_config.py

@@ -500,7 +500,9 @@ def load_model_config(
 
 # Pre-computed .venv_t5 paths and backend dir for subprocess version switching.
 # Vision check uses 5.5.0 (newest, recognizes all architectures).
-_VENV_T5_DIR = str(Path.home() / ".unsloth" / "studio" / ".venv_t5_550")
+from utils.paths.storage_roots import studio_root as _studio_root  # noqa: E402
+
+_VENV_T5_DIR = str(_studio_root() / ".venv_t5_550")
 _BACKEND_DIR = str(Path(__file__).resolve().parent.parent.parent)
 
 # Inline script executed in a subprocess with transformers 5.x activated.